Media handing devices that process media documents and bunches of media documents after separating the media documents for individual processing downstream within the media handling devices. Media handing devices include a variety of integrated components. One type of media document is a banknote or currency note (note).
As the note is processed through the media handling device, a variety of sensors are activated and deactivated to track movement of the note and indicate where the note is located along the transport pathway.
Typically, track sensors or photodiode (emitter) and phototransistor pairs, located on the same or opposing sides of the document track are activated before and/or after media handling components for purposes of transmitting a presence of the note on the track as signals to integrated controllers within the media handling devices.
Depending on the location of a note along the pathway, other devices may be activated, such as a media validation module (device) located in a designated area along the pathway. The media validation module may include cameras, sensors (Infrared, Ultraviolet (UV), etc.) and Light Emitting Diodes (LEDs) that illuminate the face of the note to capture different characteristics of the note for purposes of determining whether the note is counterfeit (fake) or unfit in some manner (excessively damaged).
Infrared security features are increasingly becoming common security features that are integrated into bank notes. Yet, validating an integrated infrared security feature produces far too many false positives for genuine notes. This is so, because the distribution of pixel intensities measured when the note is illuminated with an infrared light produces a low dynamic range for the infrared security feature and large variations for normal wear and tear (soiling, aging effects, etc.) conditions present on the note.
Thus, determining whether a note is genuine and/or in an acceptable condition (fit) for being accepted for a transaction within a media handling device is problematic when the note includes infrared security features combined with other contaminants. As a result, conventional media handling devices have higher than desired rejection rates and lower than desired acceptance rates for notes having infrared security features combined with other contaminants.